Patch "perf tools: Dont stop PMU parsing on alias parse error" has been added to the 4.4-stable tree

Patch "perf tools: Dont stop PMU parsing on alias parse error" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    perf tools: Dont stop PMU parsing on alias parse error

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     perf-tools-dont-stop-pmu-parsing-on-alias-parse-error.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 940db6dcd3f4659303fdf6befe7416adc4d24118 Mon Sep 17 00:00:00 2001
From: Andi Kleen <ak@linux.intel.com>
Date: Wed, 17 Feb 2016 14:44:55 -0800
Subject: perf tools: Dont stop PMU parsing on alias parse error

From: Andi Kleen <ak@linux.intel.com>

commit 940db6dcd3f4659303fdf6befe7416adc4d24118 upstream.

When an error happens during alias parsing currently the complete
parsing of all attributes of the PMU is stopped. This is breaks old perf
on a newer kernel that may have not-yet-know alias attributes (such as
.scale or .per-pkg).

Continue when some attribute is unparseable.

This is IMHO a stable candidate and should be backported to older
versions to avoid problems with newer kernels.

v2: Print warnings when something goes wrong.
v3: Change warning to debug output

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/1455749095-18358-1-git-send-email-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 tools/perf/util/pmu.c |   15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -283,13 +283,12 @@ static int pmu_aliases_parse(char *dir,
 {
 	struct dirent *evt_ent;
 	DIR *event_dir;
-	int ret = 0;
 
 	event_dir = opendir(dir);
 	if (!event_dir)
 		return -EINVAL;
 
-	while (!ret && (evt_ent = readdir(event_dir))) {
+	while ((evt_ent = readdir(event_dir))) {
 		char path[PATH_MAX];
 		char *name = evt_ent->d_name;
 		FILE *file;
@@ -305,17 +304,19 @@ static int pmu_aliases_parse(char *dir,
 
 		snprintf(path, PATH_MAX, "%s/%s", dir, name);
 
-		ret = -EINVAL;
 		file = fopen(path, "r");
-		if (!file)
-			break;
+		if (!file) {
+			pr_debug("Cannot open %s\n", path);
+			continue;
+		}
 
-		ret = perf_pmu__new_alias(head, dir, name, file);
+		if (perf_pmu__new_alias(head, dir, name, file) < 0)
+			pr_debug("Cannot set up %s\n", name);
 		fclose(file);
 	}
 
 	closedir(event_dir);
-	return ret;
+	return 0;
 }
 
 /*


Patches currently in stable-queue which might be from ak@linux.intel.com are

queue-4.4/perf-tools-dont-stop-pmu-parsing-on-alias-parse-error.patch
queue-4.4/x86-pci-mark-broadwell-ep-home-agent-pcu-as-having-non-compliant-bars.patch
queue-4.4/pci-disable-io-mem-decoding-for-devices-with-non-compliant-bars.patch